The problem: USB pen drive not detected
Have you got mad with your pen drive because it can’t be detected or recognized by
your computer? If you fall into this issue, you’ll lose access to all files and
folders saved on the USB pen drive. Definitely you want to work it out to make your
pen drive readable again and regain your data. Before I show you how to fix pen
drive not readable, I’d like to share the probable reasons for the problem.
Reasons and quick fixes for "USB pen drive not detected” issue
When you find your USB pen drive not detected on your computer, there are several
probable reasons:
1. There’s a problem with the USB port: in this situation, you may
plug your USB flash drive into different ports to see if a particular port is
damaged. You can get it repaired at the computer manufacturer’s repair center.
2. There’s a problem with the USB driver: in this case, you can use
Device Manager to check the status of your USB driver. See if there's a
yellow exclamation mark next to your flash drive in Device Manager, which indicates
there is a problem with the driver. Right click on the device and select Properties to
gain specific error message.
3. There’s a problem with the USB device:
• USB device is damaged physically: in this circumstance, you
can hardly fix the corrupted pen drive by yourself. A professional data recovery
service might be a nice choice.
• USB device is attacked by virus: at this time, you should
kill the virus with antivirus software.
• USB device is formatted improperly: for this reason, you can
find detailed solution in the next part.
Now you have the basic opinion about the issue pen drive not readable, let’s get
straight to how to repair pen drive not detected.
How to repair pen drive not detected if not formatted correctly?
At this part, I’ll focus on the last reason mentioned above—USB device is formatted
improperly. By “formatted improperly”, I mean the USB pen drive suddenly loses its
partitions or becomes a RAW drive due to a virus attack or abrupt removal, or simply
is assigned a used drive letter. I’ll show you how to repair pen drive not
detected in the three situations separately.
AOMEI Partition Assistant Professional as a comprehensive partition manager can assist you in all the
situations. Learn detailed steps to fix USB flash drive not recognized in Windows 10
below. These methods apply to other Windows operating systems as well. (PS.: The Demo Version is available for your free download)
Situation 1. No partitions on the USB pen drive
This problem can be solved by creating partitions on the USB flash drive or just
recovering the partitions:
✔Create partitions
1. Connect your USB pen drive to your computer. Install and run AOMEI Partition
Assistant. Right click on the unallocated space and select “Create Partition”.

2. In the pop-up window, you can set the partition size, drive letter and file system
for the new partition. To adjust the partition size, you may drag the right or left
edge of the partition as shown below. For more settings like partition label and
partition type (primary or logical), you may click “Advanced<<” button.

3. Click “Apply” to view pending operations and then “Proceed” to commit the
operations.

✔Recover partitions
1. Click on “Partition Recovery Wizard” on the left-hand pane. Choose
the USB disk from which you want to recover the accidentally deleted or lost
partitions. Click “Next” to continue.


2. Select a search mode in the pop-up window. “Fast search” is recommended for
saving time.

Tip: If you can’t find those deleted or lost partitions by “Fast
Search”, try another way: Full Search.
3. Tick the partition which you want to recover and click “Proceed” to execute
the operation.

Situation 2. USB pen drive in RAW
This error can be fixed by reformatting the USB flash drive. Keep in mind that format
will destroy all the data stored on the USB drive, so it’s essential to back up all
the important files and data before you do. The free backup software—AOMEI Backupper Standard could help you create a backup for those data. Now follow the
guidance below:
1. Right click the USB pen drive that you need to format and hit “Format
Partition”.

2. In the pop-up window, you can name the USB drive by editing “Partition Label” and
change file system based on your needs. Click “OK” to continue.

Tip: FAT32 ensures cross-platform compatibility while NTFS supports
a single file size over 4GB.
3. Click “Apply” to view pending operations and then “Proceed” to commit the
operations.

Note: You can also fix “unable to format external hard drive RAW” via AOMEI Partition Assistant command lines.
Situation 3. USB pen drive is assigned a used drive letter
This issue can be resolved by changing the drive letter:
1. Right click the USB pen drive which you want to give a new drive letter to, select
“Advanced” and then “Change Drive Letter”.

2. Select a new drive letter in the pop-up window. You can choose whichever drive
letter you like except the ones that are occupied by other drives.

3. Click “Apply” to view pending operations and then “Proceed” to commit the
operations.

Conclusion
Now you know how to repair pen drive not detected. You can find the corresponding
solution according to the exact cause from this page. With AOMEI Partition
Assistant, you are able to convert primary partition to logical in Windows 7, fix Windows 7 blue screen after SSD install and so on. Go for this tool and you won’t
regret!